A flight management system (FMS) is a fundamental part of an aircraft which is used to control a navigation of the aircraft. The FMS may hold a flight plan of the aircraft, and allow the pilot to modify the flight plan as required during the flight. The FMS uses various sensors to determine a position of the aircraft. Given the position and the flight plan, the FMS may guide the aircraft along the flight plan or a flight path. The FMS is normally controlled through a small screen and a keyboard. The FMS also may display the flight plan on an electronic flight instrument system (EFIS), navigation display (ND) or multi-function display (MFD). Further, the FMS may compute predicted speed, altitude, fuel consumed along the flight plan, and so on.
An equi-time point (ETP) may be computed by the FMS to safely navigate the aircraft, where the ETP may provide a point from which the time to fly to a first reference point (e.g., a first airport) is substantially equal to the time to fly to a second reference point (e.g., a second airport). Accordingly, the ETP may act as an advisory for the pilot during emergency situations where an emergency landing may be required. Currently, publicly visible methods for computing such a point appear to use a simplified formula based on many approximations. Further, the method seems to assume the flight to each reference point as a constant speed flight, where the wind factor, aircraft characteristics, and other flight related factors may be ignored. Thus, there may be room for an error in determining the ETP.